Of those tested daily, from 7.5 percent to 12 percent generally test positive, although some days it has been as high as 15 percent, Mell said during a seminar on substance abuse in the workplace Thursday at the Sheraton Four Points Hotel in Hagerstown.

Six speakers, including a local lawyer, an addictions specialist and two law enforcement officers, covered issues related to workplace substance abuse policies and testing.

A joint effort of the Hagerstown-Washington County Chamber of Commerce and the Greater Hagerstown Committee, the seminar attracted more than 50 local business people and public officials.

Advertisement

Mell, who did drug testing for the government when it was first instituted in the military in the early 1980s, focused on the history of drug testing and how it's done.

While a positive result is considered "100 percent accurate" - having been arrived at using two different testing methods - a negative result doesn't necessarily mean the person is drug-free, he said.

It could mean there wasn't enough of the tested-for drugs in the urine to constitute a positive result, or that the applicant did something to mask the drug, Mell said.

The most common effort to skew results is to drink a lot of fluids to dilute the urine and, as a result, the drug concentration, he said.

Sometimes donors try to pass off samples that don't belong to them or add chemicals, like pyridinium and nitrite, or more common substances, including bleach, ammonia and acid, to the urine, Mell said.

All samples undergo an initial immunoassay screen to determine whether the various classes of drugs are "present," Mell said.

A drug can show up on a test yet not be considered present if it is under the particular lab's cutoff amount for that drug, he said.

For example, Hagerstown Medical Laboratory's cutoff amount for marijuana is 50 nanograms per milliliter, according to a chart he displayed. For cocaine, it's 300 nanograms per milliliter.

Those amounts are relatively low, Mell said.

Because there are sufficient legal sources that would cause a positive result in the opiates class, including poppy seeds and cough syrup, the cutoff amount for opiates has been raised to 2,000 nanograms per milliliter, he said.

If a sample tests positive for a drug class, it undergoes a second, more specific test using a different analytical method, Mell said.

Because the body tries to get rid of whatever it can't use, testing can detect only relatively recent use of cocaine and marijuana - the most commonly detected drugs, he said.

Cocaine is eliminated from the system in two to four days, Mell said.

The elimination period for marijuana use ranges from three to four days for a single use to two to three weeks for frequent use, he said.

Attorney William Barton focused on the legal aspects of testing for both the presence of illegal substances and abuse of legal substances, like alcohol and prescription drugs.

Although testing of government employees has been contested as a Fourth Amendment issue, the amendment's search and seizure prohibition wouldn't apply to private employers, Barton said.

Private employers in Maryland have to comply with only one state statute regarding drug testing, he said.

After listing liabilities of substance abuse among employees - including decreased productivity and increased accident rates - he recommended employers have a written, detailed substance abuse policy that has been reviewed by a lawyer.

It should include a statement of the company's commitment to a drug-free workplace, strict prohibition of possession, use or distribution of any amount of illicit drugs and a statement of the consequences, which can include termination, Barton said.

The most effective policies also will contain a mechanism for testing, which could range from pre-employment testing, to testing after an accident or because of reasonable suspicion of use to periodic testing of all employees on a random basis, he said.

Random testing, while the most effective in detecting substance abuse problems, is also the most controversial option and responsible for the majority of litigation, Barton said.

Considering intensifying its anti-drug policy to include random drug testing of employees, Williamsport-based Redland Brick sent controller Sherry Harper to the seminar on a fact-finding mission.

Thanks to the variety of speakers, Harper said she was able to gather a lot of information as a starting point.

But there are a lot of legal and other issues for the company to consider, she said.